Single contact keyboard transmitter



June 27, 1933. E. P. BANCROFT SINGLE CONTACT KEYBOARD TRANSMITTER Filed Aug. 6, 1931 5 Sheets-Sheet 1 JTW N UE

INVENTOR ERWIN P. BANCROFT ATTORNEY June 27, 1933. E. P. BANCROFT SINGLE CONTACT KEYBOARD TRANSMITTER Fild Aug. 6, 1931 3 Sheets-Sheet 2 INVENTOR ERWIN P. BANCROFT BY ATTORNEY I June 27, 1933. E, P, BANCROFT 1 ,915,280

SINGLE QONTACT KEYBOARD TRANSMITTER Filed Aug. 6, 1931 3 Sheets-Sheet 3 FIG. 5

INVENTOR ERWIN P. BANCROFT ATTORNEY Patented June 27, 1933 r NITED STATES PATENT OFICE P. BANCROFT, OF BROOKLYN, NEW YORK, ASSIGNOR TO INTERNATIONAL COM- MUNICATIONS LABORATORIES, INC., OF NEW YORK, N. Y., A CORPORATION OF NEW YORK 7 SINGLE CONTACT KEYBOARD TRANSMITTER.

Application filed August 6, 1981.

My invention relates to improvements in single contact keyboard transmitters. The object of my invention is the provision of a transmitter which is simple and reliable in its operation.

The transmitter comprises the usual keyboard levers which, when depressed, operate code or permutation bars in certain combinations. These bars engage or cooperate with corresponding slidable contact controlling of the contact controlling members started by the depression of the first key-lever, a second key-lever may be depressed without upsetting or interfering with the signals corresponding to the first key-lever depressed. Further, the arrangements are such that the signals represented by the second key-lever will be transmitted immediately following those corresponding to the first keylever, regardless of whether or not the second keylever is held depressed.

Provision is also made for locking the code bars and/or the universal bail, after the de- I pression of a key-lever, for a length of time sufficient to guard against any possible interference with the signals corresponding thereto by the depression of succeeding key-levers before the contact controlling members have been properly set.

* According to one arrangement of the invention, the contact controlling members may nake successive revolutions without stop- .oing, providing the key-levers are operated in sufficiently rapid succession. Means are also provided for causing the rotating contact Serial No. 555,490.

controlling members to stop momentarily be tween each rotation, in order to operate with certain types of receivers which operate in unison with the transmitter.

Various features of my invention will be noted from the description to follow.

My invention illustrated in the accompanying drawings, wherein Fig; 1 shows a plan View partly in section of the rotating contact controlling members.

Fig. 2 shows the co-operation between the contact controlling members and the ends of the permutation bars. Fig. 3 shows a section of Fig. 1, on line 33. v

Fig. 4 shows a side View of the clutch mechanism and the contact controlling members.

5 shows a View, partly in section, on line 55 of Fig. 4.

Fig. 6 shows a left end view of Fig. t.

Fig. 7 shows a modification of the clutch mechanism shown in Fig. 5.

Fig. 8 shows a modification of the arm 25 of Fig. 7.

Referring to Figs. 1 to 6, 1 is one of a number of key-levers (one key-lever for each character of the code). Mounted for transverse movement directly below the key-levers is a group of permutation bars 2, one for eachimpulse of the code to be transmitted. These permutation bars have notches and cams so arranged that thejdepression of'any key-lever will move the permutation bars into the selected and non-selected positions. In other words, the permutation bars are arranged so that they remain set in the position determined by the last key-leverv depressed. Opposite the ends of the permutation bars 2 is a cylinder 3 which carries pins 5 in corresponding slots 6. Cylinder 3 is rigidly fastened to shaft 4. Mounted for longitudinal movement within cylinder 3 are five slidable rods 7 and a sixth slidable rod 8. Pins 5 are attached to these slidable rods 7 one pin being attached to each rod. Rod 8 has no corresponding pin 5, but is arranged to be spring-pressed into the operated position.

The arrangement of the permutation bars 5 ride along the side of the ends of bars 2.

This is shown more clearly in Fig. 2, the ends, as indicated, serving as cams to move the pins 5 from the normal non-selected position to the selected position. The movement of any of the pins 5 into the selected position moves their corresponding rods 7 into a similar position and causes the rod 7 to extend beyond the end of drum'3.

Mounted on pivot 15 and opposite the end of the drum 3 is a lever 9 carrying contact arm 10 on which contacts 11 are mounted and which cooperate with stationary'contacts 12 and 13. A cam surface on the end of contact lever 9 co-operates with pins 7 and 8 to determine the position of contact 11.

Thus, as drum 3 revolves, the selected pins 7 will cause contact lever 9 to move in a clockwise direction to close contacts 11 and 12. The pins 7 which are not selected will-not come in contact with contact lever 9 and it will be spring-pressed in a counter clock-wise direction to close contacts 11 and 13. Rod 8, being normally in the operated position, will always cause contacts 11 and 12 to be closed. Between rod 8 and the first rod 7, reading in a clock-wise direction, there is a space which will allow contacts 11 and 13 to close each time the drum 3 revolves. Drum 3, in Fig. 1, is shown in the normal or stop position. A face cam 51 is located adjacent to the end of drum 3 nearest contact lever 9 in such an angular position that, immediately after the pins 7 7 pass the contact lever9, any that have been selected will be restored to the normal or unselected position. Thus, in the stopped position of drum 3, allpins 7 will be in the non-selected position."

The depression of key-lever -1 sets the permutation bars and releases the shaft 4 for rotation. The rotation of shaft 4 first opens contacts 11 and 12 and closes contacts 11 and 13. This will be followed by five intervals, during which contact 11 will close either on contact 12 or 13, depending'uponthe position of the rods 7. This, in turn, will be followed by an interval during which contacts 11 and 12 will always be closed. In other words, for each revolution of the cam shaft,-the signals transmitted will consist of an invariable signal impulse followed by permutations of five impulses corresponding to the letter to be transmitted and an invariable impulse.

Referring now to Figs. 1 and 3, shaft 1 which carries drum 3 is shown rigidly connected to one part of a single revolution clutch 20, the other part of clutch 20 being rigidly attached to shaft 4' which, in turn, is connected to a source of power, such as an electric motor. An example of the type of clutch which may be used is disclosed in ward movement of bail 16.

United States Reissue Patent No. 17 ,725, granted July 8, 1930 to F. G. Creed. In Fig. 3, only one of the permutation bars 2 is shown, it being understood that there are as many permutation bars 2 as there are elements of the code. The depression of the key-lever 1 operates the permutation bar 2 in the manner already described, and at the end of its depression causes the universal bail 16 to move downward. This downward movement of bail 16 causes clutch release lever 18 to rotate in a clockwise direction and, thereby, to release clutch 20, coupling shafts l and 4. Clutch release lever 18 is cammed in the clock-wise direction by pawl 21. This pawl may be adjusted by means of the eccentric 29 and operates only on the down- The movement of clutch release lever 18 in the clock-wise direction also allows clutch release lever lock 22 to lock the clutch release lever 18 in the operated position. Lever 22 will rotate slightly in the counter clock-wise direction, causing an extension of lever 22 to enter either slot 23 or 24 in permutation bars 2, dc pending upon whether the permutation bars are in the unselected or selected positions, respectively. During this first portion of the revolution of the drum 3, the selection is transferred from the permutation bars 2 to the rods 7 of the drum 3. As soon as the selection has been transferred to the rods 7, a pin 26 on clutch 20 rotates lever 22 in a clockwise direction, unlocking clutch release lever 18 and the permutation bars 2. accomplished a second key-lever may be depressed. In this case, the same procedure takes place as already described, except that the shaft 4 may not have completed its revolution. In this case, the clutch release lever 18 will be locked in the operated position, and the permutation bars '2 in the position determined by the depression of the second key. This condition will maintain until the shaft 4 has completed its revolution and enough of the succeeding revolution to transfer the second selection to the rods 7 and restore the clutch release lever 18 and unlock the permutation bars.

With the mechanism just described, two key-levers may be depressed in rapid sue cession without mutilating either character and without the necessity of maintaining the second key-lever operated until the signal corresponding to the first key-lever has been transmitted. The only requirement here is that the subsequent key-lever cannot be depressed until the selection set up by the proceeding key-lever has been transferred to the drum '3. This transfer occurs during the When this is greater than the speed at which the transmitter' is set to run. This locking arrangement, however, will not in any way prevent the operator from momentarily'operating at amuch higher speed. Further, if successive keyelevers are depressed before the revolution of shaft 4 corresponding to the preceding key-lever depression has been completed, shaft 4 will continue to rotate and an unbroken succession of code signals will be transmitted.

Lever 25, mounted on pivot 32, operates in conjunction with pin 26 to prevent clutch 20 represents a clutch mechanism, for example, the clutch disclosed in United Stat-es ReissuePatent No. 17 ,725, granted July 8, 1930 to F. G. Creed, which is rigidly secured to shaft 4. 18 is a stop member which engages the dogs 19 of the clutch 20 to disengage the same from the driving shaft 4. The nose 18 is carried on a lever 18 having two cars 41 and pins 44 thereon. Carried 3 on the same pivot with lever 18 is an operating lever 40which is held in engagement with lever 18 by a spring 43 operating in conjunction with the pins 44. The universal hail 16 is operated by each depression of the key levers 1. Bail 16 carriesv a dog 21, having. at its extreme left-hand end an inclined surface which co-operates with a similar inclined surface on lever 40 each time the bail is depressed to cause lever'40 to turn about its pivot in a clock-wise direction. The movement of lever 40 in the clock-wise direction tensions spring 43 and thereby tends to move lever 18 in a clock-wise direction to release the clutch mechanism for operation. With the mechanism in the position shown, the depression of the bail 16 will cause the lever 18to. operate immediatelyto release the clutch. The movement of lever 40 to the left allows a nose on bell crank 22 to lock lever 40 in the operated position. A pin 26 carried byfclutch housing 20 will contact with the vertical. arm of lever 22 after shaft 4 has rotated a predetermined distance, causing lever 22 to rotate about its pivot in a the extension 42 of lever in front ofthe ear 41 of lever 18. If now the bail 16 is operated before the shaft 4 has made a complete revolution, lever will be rotated in a clock-wise direction to tension spring 43 and will be locked in the operated position by lever 22. Spring 43 will tend to rotate lever 18 in a clockwise direction, but lever 18 will be restrained from movement due to the fact that the extension 42 of arm 25 is in front of the car 41. The nose 18 of lever 18 will, therefore, be held in a position to engage the dog 19 of the clutch 20 at the end of the revolution of shaft 4, thereby causing the clutch to be disengaged and shaft 4 to stop. As soon as shaft 4 reaches the stop position, a projection on lever 25 drops into a detent on the clutch housing 20, allowing lever 25 to move upward and to disengage the extension 42 from the ear 41 of lever 18. Lever 18 will then rotate in a clock-wise direction and release the dogs 19 to allow the clutch mechanism to again engage. As already stated, after a predetermined part of the revolution of shaft 4, the pin 26 will rotate l lever 22 in a clockwise direction to release lever 40 and thereby allow levers 40 and 18 to be restored to their normal positions, as shown.

Lever 22 carries an extension 45 which cooperates with a bell crank 46 pivoted at 47. With the mechanism in the position shown, the bell crank 46 is held in such a position that the extension is clear of projection 49 carried by the universal. bail'16. As soon as the universal bail 16 is depressed, thereby rotating lever 40 in a clock-wise direction and allowing lever 22 to rotate in a counter clock-wise direction to lock lever 40 in the operated position, the extension 45 of lever 22 is raised and allows bell crank 46 to rotate in a clock-wise direction under the influence of spring 48. Since the universal bail16 at this time is in the depressed position, the extension 50 will come in contact with the edgeof projection 49 on bail 16. Howevenas soon as bail 16 is released, the extension 50 will move underneath the projection. 49 and thereby prevent the depression of bail 16 before lever 22 has been rotated to release lever 40. l/Vith the mechanism in the position shown, this interfering with the operation of bail 16 will not accomplish any useful. purpose. However, if we assume that the shaft has been previously released and that the universal bail is depressed and re leased a second time before the completion of the revolution of the shaft 4, the bell crank 46 will move the extension 50 underneath the projection 49 on bail 16 and thereby prevent a further depression of bail 16 until after the shaft 4 has started on its second revolution and lever 22 has been operated to release both the lever 40 and the bell crank 46. Since this latteroperation occurs during the'first part of the revolution of shaft 4, the bail 16 will be prevented from operating only long enough to insure that the, signals set up by the previous depression of the key-lever havebeen transferred to; the transmitting mechanism.

- I It is evident from the foregoing description that the shaft 4 will be stopped at the end of each revolution, but, if a key-lever has been depressed before the completion ofthe revolution, it will start again, the actual stop time depending upon the time required for the operation of levers 25 and 18 and for the dogs 19 to engage. The stopping of the transmitting shaft each revolution will insure that the transmitter cannot make more revolutions than the receiver, assuming the latter to be operating at the same speed as the transmitter, and will thereby prevent the transmitter from getting ahead of the receiving mechanism. 7

Fig. 8shows a modification of the mechanism of Fig. 7 whereby the depression of arm 25 by the cam on the clutch housing 20 will rotate lever 18 in a. clock-wise direction through the agency of roller 42' and the inclined surface 41.

\Vhat is claimed is: r r 1. A signal transmitter comprising a rotat able drum provided with slidable contact controlling members, a permutation bar individual to each of said contact controlling members, means for positioning said permutation bars to cause them to be engaged by said contact controlling members, and means for momentarily locking the permutation bars when operated. a a

2. Asignaltra'nsmitter comprising a rotatable drum, means for starting and stopping the rotation of said drum, a plurality of permutation bars co-operating with said drum, means for operating said permutation bars, means for starting the rotation of said drum, means for locking said permutation bars when operated, and means for unlocking s a-id permutation bars after the rotation of said drum has startedand before it has stopped. r w

3. A signal transmitter comprising a series of rotatable contact controlling members, a contact arm, a permutation bar individual to each of said contact controlling members, means for operating said permutation bars to pause them to be engaged by said contact controlling members, the engagement of which controls the operation of said contact arm, and means for momentarily locking said permutation bars after their operation.

4. In a keyboard transmitter the combination comprising a plurality of rotating contact controlling members, a plurality of permutation bars, and key-levers, .means controlled by said key-levers for starting the rotation of said contact controlling'members and for locking said permutation bars, and means for unlocking said bars after the rotation of said contact controlling members has started. i 5. In a keyboard transmitter the combination comprising a plurality of rotating contact controlling members, a plurality of pertation of said contact controlling members and for locking said permutation bars, and means for unlocking said bars after therotation ofsaid contact controlling members has started, the ,re-operation of said key-levers duringithe first rotation serving toagain lock 1? said permutation bars and to permit a second rotation of said contact controlling members.

7 :In akeyboardtransmitter the combination comprising a plurality of rotating contact controlling members, a plurality of permutation bars and key-levers, means controlled by said key-levers for starting the rotation of said contact controlling members and for locking said permutation bars, means for unlocking said bars after the rotation of said contact controlling members has started, the re-operation of said key-levers during the first rotation serving to again lock said permutation bars and to perm1t a second rotation of said contact controlling members, and means for insuring a momentary stopping of the contact controlling members between successive rotations.

' 8. In a keyboard transmitter the combination comprising a rotatable member, a plurality of key-levers, means'controlled by said key-levers for starting the rotation of said member, the re-operation of said key-levers during said rotation causing said member to make a second rotation, and means for causing the said member to momentarily stop between successive rotations. v

9. In a keyboard transmitter the combination comprising a rotatable member, a plurality of key-levers, means controlled at each operation of said key-levers for causing a corresponding rotation of said member, and means for momentarily stopping said member between each complete rotation.

10. In a keyboard transmitter the combination comprising a rotatable member, a plurality of key-levers, means controlled at each operation of saidkey-levers for causing a corresponding rotation of said member, and means for momentarily stopping sald member between each Complete rotation, the rotation of said member being independent of the positions of said key-levers after their operation.

11. In a keyboard transmitter the combination comprising a plurality of rotating contact controlling members, a plurality of key-levers, for setting said contact controlling members, a bail operated by said keylevers, means controlled by the operation of said bail for starting the rotation of said contact controlling members, and means controlled in the starting of the rotation for momentarily locking said bail until after the 1 setting of said contact controlling members.

12. In a keyboard transmitter the combi- 'nation comprising a plurality of rotating contact controlling members, a permutation bar individual to each of said contact con- 30 trolling members, a plurality of key-levers and a member operated thereby, means controlled by the operation of said member for starting the rotation of said contact controlling members, and means controlled in the starting of said rotation for momentarily locking said permutation bars.

13. In a keyboard transmitter the combination comprising a rotatable member, a plurality of key-levers, means controlled at each operation of said key-levers for causing a corresponding complete rotation of said member, the rotation of said member being independent of the positions of said keylevers after their operation.

I 35 14:- In a keyboard transmitter, the combination comprising a plurality of key levers and a bail operated thereby, contact controlling members set by the operation of said key levers for transmitting signals, means for lib momentarily locking said bail to prevent its re-operation by said key levers until after the setting of said contact controlling members.

15. In a keyboard transmitter according to claim 12, characterized in this, that said member is also momentarily looked under control of said last-mentioned means.

16. In a keyboard transmitter the combination comprising a plurality of rotating Contact controlling members, a permutation bar individual to each of said contact controlling members, a plurality of key-levers and a member operated thereby, means controlled by the operation of said member for starting the rotation of said contact controlling members, and means controlled in the starting of said rotation for momentarily locking said member.

In Witness whereof, I hereunto subscribe my name this 31st day of July 1931.

ERWIN P.- BANCROFT. 

